The present invention concerns a process for running an anionically or cationically catalytically accelerated gas phase reaction, a process for running catalytically accelerated gas phase polymerization, as well as applications of the process and polymerizates produced according to the process of the invention.
The catalysts in anionically or cationically catalytically accelerated gas phase reactions or in a reactor with a wet suspension are generally arranged on supports and enclosed on this account.
In the case of catalysts arranged on supports for running so-called heterogeneous catalysis, the support together with catalyst is held in the gaseous reaction mixture by means of a fluidized bed. Especially in polymerization in the gas phase, like production of polyolefins, catalysts arranged on supports are used in which so-called metallocene-based catalysts have recently come into use, which are arranged on silica gel or magnesium chloride as support particles, among other things. The major advantage of these catalysts based on metallocene compounds is that selective or controlled reactions are made possible and production of polymers with substantially improved properties relative to now common polymers is made possible, especially in terms of elasticity, heat defection temperature, hardness, etc.
However, the production of such catalysts based on the metallocene compounds is still very costly and intricate in that the substance forming the catalyst must initially be deposited on the support and then activated, for example, by alkylation agents or with so-called Lewis acids. However, production of the corresponding polymers, like polyolefins, based on such metallocene catalysts, is therefore also very expensive.
When ionic catalysts dissolved in solvents are used, there is a problem that the reaction rate must generally be adversely affected by the presence of a solvent and the counterion. Moreover, the solvent can partially react with the catalyst or form complexes by addition to the active anion and cation so that the activity of the catalyst is reduced. In addition, the solvent destroys favorable electrostatic interaction that exists in the gas phase. These catalysts are generally so-called Ziegler-Natta catalysts and catalysts appropriate for running so-called methathesis processes.
It is therefore a task of the present invention to propose a process by introducing anionic or cationic catalysts to a gas phase reaction mixture for catalytic acceleration of the reaction without the drawbacks just described.
The invention provides a process for carrying out an anionically or cationically accelerated reaction in the gas phase where the catalyst is introduced to the gaseous reaction mixture as a free anion or cation without its corresponding counterion and at least largely solvent free.
In this process the catalyst can be activated in a solvent and the solvent and the counterion of the anion or cation catalyst are then largely removed before introduction of the reaction mixture. The catalysts can be introduced into the gaseous reaction mixture by electrospray ionization, thermospray ion vaporization or by atmospheric pressure ionization.
The process of this invention can be performed in several reaction regions or reaction stages arranged in succession to carry out a chain reaction of polymerization reaction triggered by the catalyst or accelerated with the catalyst.
The reaction to be accelerated can be a metathesis reaction, a metathesis ring-opening polymerization or a gas phase polymerization reaction.
In the process of this invention the catalyst can be a Ziegler-Natta catalyst, preferably a metallocene catalyst.
The process of this reaction can be employed for the production of a polyolefin.